let s be SCM-State; :: thesis: for t being Element of SCM-Data-Loc
for u being Integer holds (SCM-Chg s,t,u) . NAT = s . NAT
let t be Element of SCM-Data-Loc ; :: thesis: for u being Integer holds (SCM-Chg s,t,u) . NAT = s . NAT
let u be Integer; :: thesis: (SCM-Chg s,t,u) . NAT = s . NAT
A1: ( SCM-OK . NAT = NAT & SCM-OK . t = INT ) by Lm4, Th7, Th8;
{t} = dom (t .--> u) by FUNCOP_1:19;
then not NAT in dom (t .--> u) by A1, NUMBERS:27, TARSKI:def 1;
hence (SCM-Chg s,t,u) . NAT = s . NAT by FUNCT_4:12; :: thesis: verum